The growing popularity of milk chocolate, and even to produce it in large volumes is still in use powdered milk, and milk is widely used grit (granular mixture of cocoa, powdered milk and sugar) due to its quality and special flavor.
In the confectionery industry, condensed milk with sugar and without sugar is widely used. Recycled milk is also used, but in this case it is necessary to be very careful when preparing the dispersion. Products are increasingly being used from whey. Liquid milk is rarely used, since a large amount of water is required for its condensation in evaporators. Nevertheless representatives of some firms assert that the best milk sweets are made on the basis of liquid milk. Many enterprises use fresh cream and other dairy products - butter and milk fat, lactose and modified milk protein.
Confectionery production technologist should know the characteristics and composition of the various dairy products used, in which, we hope, will help him set out below a summary. In cases where more information is required about any kinds of raw materials, you can refer to the works referred to at the end of this chapter, and other literature available in libraries.
The most common dairy product in most countries is cow's milk, but in some regions are used and milk from other species. For example, in India and some Middle Eastern countries use buffalo milk, and in many countries widespread goat milk.
10.1 Table. The average composition of cow's milk in the UK
lactose, casein / Albumin ash
Water,% Fat,% (protein)
By [3-5] 87,61 3,62 8,77
87,70 3,53 4,30 3,67 0,80
On  87,70 3,61 4,65 3,29 0,75
10.2 Table. Fat content of milk from cows of various breeds
Breed Fat, SNF%,%
AirShire (Ayrshire) 3,7; 4,3 8,8; 8,8
Frizskaya 3,5 8,6
Gernzeyskaya 4,5; 5,1 9, 1; 9,3
Zherseyskaya 5,5 9,5
Golştinskaya 3,7 8,5
Shorthorn 3,5 8,7
10.3 Table. The average composition of milk of other species
Milk Water,% Fat,% Lactose,% Protein,% Ash,%
Buyvolits 82,9 7,5 4,7 4,1 0,8
Козье 85,3 4,9 4,8 4,1 0,9
Women 88,2 3,3 6,8 1,5 0,2
The average composition of cow's milk in the UK is shown in Table. 10.1. Under the influence of seasonal changes in the milk with the highest fat content (average 4%) is produced in the autumn, and the lowest (average 3,5%) - spring; index SOMO also highest in autumn (8,8%) and below - spring (8,6%).
Milk cows of different breeds vary considerably - particularly fat differs milk cows and dzherseyskoy gernzeyskoy rocks (the fat content of milk of cows of different breeds is given in Table 10.2.).
The average composition of other kinds of milk is given in Table. 10.3, but the published data differ considerably, as they depend on the environmental conditions, diet, and (in the case of animal milk) on the quality of livestock operation.
Buffalo milk and goat's milk on the composition different from the cow (especially fat content and composition of mineral salts).
Milk Quality Standards
In most countries, the composition of the milk must conform to established standards for minimum fat content and SOMO.
On dairies standard composition corresponding to the requirements, is achieved by processing large batches of milk. Normative Acts provides specific categories of milk - for example "Without heat treatment (unpasteurized) "," Pasteurized "," sterilized "or" pasteurized long term storage. " Large companies producing chocolate and pastries, often themselves processed liquid milk and produce condensed milk, milk powder and dairy grits. At these companies employ technology of milk production, which is usually not only have sufficient knowledge of milk processing technology, but also tech savvy confectionery manufacture.
The proteins that make up milk (casein, albumin and globulin), are easily digested and are a source of essential protein in the diet, which is why the milk as a food product is valued so highly.
Casein, which basically gives the milk and the characteristic white color, is present as a colloidal suspension of tricalcium phosphate in the molecule and is associated with calcium. Milk casein by acid or enzyme rennin (rennet) precipitates, but if calcium is removed using an acid, the calcium, the enzyme remains bound to the protein molecule. Casein is about 80% of the total nitrogen content, which in the milk of about 2,85%.
Casein is prepared for industrial applications in plastics, adhesives, inks, paper and pharmaceuticals. In the confectionery industry, it is used as a stabilizer and egg white substitute and
included in the product, which is used for the preparation of a dry or condensed milk. 20% remaining protein is now called "whey", which consist mainly of lactalbumin and lactoglobulin. An the following composition of milk protein:
a (альфа, S1 и S2) 48
b (бета) 36
k (kappa) 13
y (gamma) 3Whey proteins (20%)p-lactoglobulin 50
other proteins 30
The stability of these proteins greatly influences the properties of milk powder. For example, lack of instant (instantizirovannogo) skimmed milk (COM) used in the composition of many beverages as liquid milk replacer may be the formation of fat clots or flocculation (flocculation) by dissolving powdered milk. This can be avoided by controlled heat treatment of fluid milk.
Denaturation of proteins has been studied in relation to the role of casein - percent of total nitrogen of precipitated at pH 4,7.
Milk casein number not subjected to a heat treatment, is 77,6%. When heated milk, this figure rises to 90% and produced from milk powder it less suitable for use in beverages (instantizatsiyu we consider below).
Lactose (milk sugar) is a natural sugar present in the milk of all mammals, but not occurring in the vegetable world. From the chemical point of view it is a disaccharide composed of dextrose (glucose), and related to galactose and reducing sugars.
Lactose is very important in terms of nutritional value, as it promotes the absorption of calcium and phosphorus in the body young and recognized as a source of sugar matter brain tissue.
difficulties, since lactose has a low solubility and specific features of the crystallization. The solubility of lactose at normal temperatures is about 16%, and at 90 ° C, this figure increases to 60%. The stretchthief lactose has two forms (a and p-lactose). The crystalline lactose is able in one of three forms: Hydrate a-lactose anhydride cc-lactose, lactose anhydride, p. Industrial lactose - is a-lactose monohydrate and anhydride obtained either by dehydration at a temperature of up to 65 93,5 ° C and low pressure, or at normal pressure and heating to 110-130 FROM. Anhydride hygroscopic, and when in contact with moist air at a temperature below 93,5 ° C it turns into a hydrate thereof, and at a temperature above 93,5 ° C - in the p-lactose anhydride (the latter is formed and when the lactose crystallizes out of the concentrated solution at a temperature above 93,5 ° C).
If not seeded, lactose crystallizes out of the solution slowly, and large sandy crystals are formed by slow crystallization. Solubility under the action of sucrose lactose significantly reduced. All these factors need to be considered if in the confectionery is expected to include lactose or have a high content of milk solids - otherwise when stored products may acquire an undesirable sandy texture.
Industrial lactose made from whey obtained from cheese production, and from the liquid remaining after the production of casein (cm. Below "Whey Products" section). This liquid is acidified and heated in the presence of activated charcoal and then filtered. The resulting material was subjected to repeated crystallization, and on how many times this is done depends on the purity of the composition.
High-quality food lactose has the following composition (%)
Lactose At least 98,0
The moisture content of 0,10-0,20
Acidity (calculated as lactic acid) 0,05-0,10
Milk contains 0,7-0,8% of mineral salts, which are represented mainly citrates and phosphates (salts of citric acid), calcium and magnesium. The data presented in the Table. 10.4. Also present and trace elements (To the, his Mp, Zn, I), which are known to play an important role in the human diet.
To avoid curdling the processing of raw materials necessary to maintain mineral balance.
|10.4 Table. Mineral salts in the milk|
Mol / l
Salts —————————- -------
all of them soluble
Milk fat, butter, fat, oils, fractionated oils fat
Important ingredients of confectionery and chocolate are butter and oil fat. Milk fat is a part of products always, when whole milk products are used - condensed milk (with sugar or without sugar), milk powder or cream. The taste and consistency of caramel, milk candy and iris is determined precisely by the presence of these ingredients. The anhydrous fat of cow's oil is an inhibitor of the graying of dark chocolate. Butter (factory) is produced by knocking down cream. Cream is separated from the milk by heating and settling or (under industrial conditions) by centrifugation.
When Interrupting broken membranes of fat and fat globules (globules) are combined. Salt is added for flavor, but it acts as a preservative. Oil can be made from sour cream or fresh cream, and the cream gives the product more powerful VCmustache / flavor.
The average composition of butter prefabricated (%):
The moisture content of 15,3-15,9
thats (added) 0,03-1,8
Protein (clot) 0,7
A unique property of the oil is that it contains a significant proportion of lower fatty acid glycerides, including oil. The slightest amount of released butyric acid gives confectionery products, is subject toconductive heat-treated, oily taste, which is determined mainly by the presence of diacetyl (CH3SOSOSN3), Formed from the cream.
A list of fatty acids that make up fat oil in the form of Glyceridov (%):
At normal temperatures, the shelf life of factory butter (both salted and unsalted) is limited, and long-term storage should be kept in the refrigerator at a temperature -10 ° C.
At normal temperatures, there is a gradual change in taste (pro- gorkans), since there is an allocation of free fatty acids. These changes are caused by the action of enzymes, the activity of microorganisms and oxidation in air. In the initial stages of damage it is easiest to estimate the degree of taste and smell, but it is also useful to determine such factors as acidity and peroxide value.
With conventional methods of fat rancidity grease cleaning oil can not be completely eliminated, even after removal of volatiles is salisty taste.
If the recipe confectionery present oil that it contains enzymes and micro-organisms makes it necessary heating or cooking of semi-finished products, as otherwise products during storage may appear very unpleasant taste.
Milk fat or cream produced by the removal of moisture butter manufacturing factory, clot, salts and other minerals. There are several methods for preparing such fat:
1) oil boiling at a temperature well above 100 ° C; This removes the moisture deposited clot and minerals, which are then filtered (motivated to pump), but as a result of applying this method often markedly deteriorates the taste;
2) Melting of oil in the tanks and discharge supernatant water; this method is uneconomical, since separation is incomplete passes;
3) Melting, washing with hot water and subsequent centrifugation.
Original oil, skimmed and ways 2 3, must undergo a thermal treatment at a temperature 93 ° C, it is necessary to destroy the enzymes. many enzymes present in the milk, and to prevent the hydrolysis reaction caused by saponification of fats (which can occur in confectionery containing Lauriiovye fats), especially important to destroy lipase. At all stages should be applied only in stainless steel equipment.
It is believed that present in the oil in an amount 0,3% phosphatides (lecithin) together with other substances contribute to a better (as compared with the use of vegetable fats) emulsified oil, a component of confectionary.
Anhydrous butter (milk or butter fat) in the solid state has a relatively long shelf life (with the proviso that dehydration was carried out properly). According to the representatives of the companies-suppliers of those products, the duration of their storage at normal temperatures can be 6-12 Months.
The moisture content of the dairy cream or fat should not exceed 0,05%. In case of excess fat in finding water in liquid form is separated, resulting in accelerated oxidation of fat on the surface. In developing the form of tanks for storage of liquid fat should include more concave bottom, which allows empty container without residue.
Fractionated butter fat
One of the current methods use excess butter is its separation into fractions of different melting points (fractionation). Product Groups whose melting point is between 10 42 to ° C. Fig. 10.1 shows the curves of the solid fat index (ITJ) Identified by nuclear magnetic resonance.
Sweetened condensed milk and sugar.
Some information about the production of condensed milk are given in the description of the preparation of dairy grits, and here we briefly describe the industrial production of condensed milk.
First, whole or skim milk for 15 min is heated at a temperature of 82-85 ° C, with pathogenic microorganisms, yeasts and molds killed, and enzymes inactivated. It should be noted that the inactivation of lipase occurs at this relatively low temperature due to the large water content (short-term high-temperature treatment can also be used). The sugar is then added to the hot milk and the solution is concentrated under reduced pressure (in vacuo). After reaching the required concentration, the liquid is rapidly cooled with continuous stirring; To prevent the appearance when storing large crystals of lactose, a primer is introduced from its finely divided crystals.
The sugar composition in the condensed milk serves as a preservative, and even in the absence of a sterile package can be expected that the product will withstand sufficiently long storage. The most favorable storage temperature below 16 ° C; summer at higher temperatures (21 ° C and above), the product thickens, darkens its color appears stale flavor (especially for products from whole milk). At observance of sanitary-hygienic requirements and the right
carrying out a preheating occurs unwanted microbiological processes.
Evaporated milk produced in the same way but the concentrated whole milk from the condensation device is homogenized still warm, allowing the fat globules evenly distributed, remaining small, i.e. separation occurs.
Concentrated milk without sugar should be sterilized in hermetically sealed containers (except in cases where it will be used within 24 hours from the time of production); as well as other types of milk, concentrated milk sugar be kept longer if it cooled to 4-7 ° C.
The composition of sweetened condensed milk
In the calculation of recipes you can use the data on the composition presented in Table. 10.5, but it is desirable nevertheless to check its chemical composition and synchronize data with information submitted by the supplier.
|10.5 Table. The composition of sweetened condensed milk|
Sweetened condensed milk in blocks
This cured varieties of condensed milk with sugar, the moisture content is reduced to 8-9 %. The use of such milk is justified in cases when it is required to be transported over long distances; it is imported mainly from the Netherlands, but in large quantities it is no longer produced.
A typical composition of the product (%):
Milk fat 18,5
The moisture content of 9,0
Almost complete dewatering of the milk used for its conservation for a long time, but the disadvantage of powdered milk is that it is rather difficult to restore it to a liquid state. Production of milk powder developed with 1900 city, have been tried many methods, but now "survived" only two groups of technologies, namely drying in a drum dryer (drum drying), and spray drying.
Drying in a tumble dryer
During drying in a drum dryer milk, concentrated to about 23% solution of solids content (ST) and past homogenization, enters the steam drums with internal heating. The drums rotate slowly, and in less than one full turn milky film loses moisture. Then this film is going to scrapers, and the obtained flakes crushed and sieved (or milled into a powder). Solubility of this product is to 80 90%.
There are various patented design drum dryers, which are said to provide more high quality and performance. In one recently developed drum dryers placed in a vacuum chamber, enabling drying at lower temperatures. As a result, less damaged proteins, milk and has higher solubility.
Roller drying milk powder used in the production of glaze on vegetable fat. This kind of milk powder absorbs less fat. Production volumes of milk powder of this type is gradually reduced due to the fact that much more efficiently produce milk powder by spray drying.
Spray drying and instantizatsiya
When spray drying the concentrated milk is sprayed with a pneumatic or a centrifugal atomizer in a large storage chamber with turbulent flow of hot air. Milk particles settle slowly in the chamber and simultaneously dries. Powder entrained with the exhausted air is separated using cyclones.
In modern designs dryers used milk, concentrated to 52%, and the temperature in the drying chamber is raised to 150 ° C. The new types of dryers the system provides a fluidized bed dryer. Due to these improvements could significantly increase productivity and more cost-effective to spend the heat.
Spray drying can be carried out in combination with instantizatsiey (improving the solubility of the dried product). In this case there arLonumeration of particles. These aggregate structures are easily wetted and dissolve rapidly in drinks such as coffee or tea.
The systems developed by the company "Niro atomizers » (A/S Niro atomizer), Дания
During the drying each droplet is transformed into a powder particle, and the larger the concentration of the liquid before it is sprayed, the greater the obtained dry milk compared to the amount of evaporated water. Therefore, an important role is played by the extent to which the head of the spray gun is suitable for use with liquids with a high content of NE.
In the drying chamber newly formed particles of powdered milk for a few seconds remain suspended in the air, until they reach the conical part of the drying chamber. Dry powder slides down the vibrating cone in 5, and then with the help of pneumatic transport arrives in a small cyclone 6. Hot air coming from the drying chamber 7, 8 enters the cyclone, where rotates at high speed, and the suspended particles are separated by centrifugal force. The resulting powder is transferred by a pneumatic transport system, and then combined with the stream leaving the cyclone at a point 9. Finished products are unloaded at the point 10
Using the first stage of drying of the powder higher humidity can reduce manufacturing costs and improve product quality. At the same time, it must be free flowing powder, which allows to let air of higher temperature without compromising the product quality.
The powder is discharged from the bottom of the main cone dryer on the first fluid bed dryer 6. From this second dryer milk enters the collector (the collector). Air is withdrawn from the fluidized bed is also fed into 7 cyclones.
This technology has already been mentioned in the "cocoa" and "chocolate a beverage." instantized (instant) skimmed milk powder is now widespread.
Multipurpose agglomeration equipment with moisture. To happened surface agglomeration of the powder from the hopper 1 pneumatically sent into the pipe agglomerator 2. Simultaneously, warm moist air enters 3 the pipe tangentially, creating a vortex flow. Speed of movement of air, the temperature and humidity can vary considerably. Having reached a certain size, the agglomerates leaving the pipe agglomerator. The surface dried agglomerates in the chamber 4, situated under the pipe agglomerator. The final drying and cooling of the powder takes place in moisturizing vibratory 5. Finally, the product passes a sieve 6, and the powder was collected from the air in the cyclone, is returned to the agglomeration chamber. Using this procedure, COM converted to instant product consisting solely of large agglomerates bulk (bulk) density of which does not exceed 0,3 g / ml.
Some newer systems. Currently, for the production of COM is used to spray dryers located inside the fluidized bed chamber.
For such equipment characteristically much lower power consumption. In the future, such systems will supersede sinter plants with moisture, as well as the old once-through systems in which an instant milk powder produced directly from liquid skimmed milk.
Washing and cleaning
Washing and cleaning equipment for the spray drying process is of paramount importance. At the top of the first dryer can accumulate partially dried milk powder, in which microorganisms can grow to high CFU values (along with other organisms may develop and Salmonella therein).
Purification Equipment (like any other dairy equipment), a steam sterilization process and cleaning solutions should be carried out very carefully.
The properties and characteristics of milk powder
Spray drying milk powder has greater solubility (99%), milk powder than the drying roller; As a rule, the solubility of protein related to the degree of denaturation and the rate at higher roller drying. Spray drying milk quality almost completely soluble in cold water, whereas the solubility in the roller drying milk it can be less than 85%.
In the past it was believed that the shelf life of milk powder by spray drying is less than that of milk roller drying, but pre-heat treatment method will significantly reduce this gap. Various different methods of heat treatment - aging at a temperature of from 73,9 ° C for accelerated 30 minutes to high heat treatment with heating to 87,8 ° C, the product holding at this temperature for 3 minutes. It is also used and UHT (UHT) - milk rapidly (in 2-4 c) is heated to a temperature of about 140 ° C (or by steam injection or by passing the milk through the heat exchanger under pressure).
Preservation properties during storage of powdered milk is related to its moisture content, with the storage temperature, and the access of oxygen. The duration of storage, particularly in the CMS may be increased by vacuum packaging or modified (nitrogen) gas environment.
The moisture content should not exceed 4%, and for long-term storage it is necessary to maintain the temperature of 7 ° C (dry milk must be packed in moisture-proof containers). The modified gas atmosphere package and the vacuum package reduce the effect of oxygen trapped by the individual powder particles during drying and dispersing inside the container in the space above the product. If a gas with inert properties (eg nitrogen) is used, then the oxygen level is reduced and, therefore, the shelf life of the product is increased. Currently COM milk is divided into low-, medium- and high-temperature treatment in accordance with the use of condensation and drying technology. Low-temperature processing of milk powder is used in applications requiring good solubility and its reconstitution in water. Powdered milk produced at higher temperatures due to its lower absorption capacity is used for the manufacture of mixed glaze and baking industry.
The composition of powdered milk
Obviously, the composition of powdered milk used depends on the composition of liquid milk. Standards of various countries may differ slightly, but the average composition of powdered milk is shown in Table. 10.6
|10.6 Table. The composition of powdered milk|
Products of whey
Whey is a by-product of cheese or casein. It is not strictly defined composition is characterized as sodium and calcium salts may be added in the production of cheese, which change in Eneral- no-salt composition of serum.
In the past, products from whey mostly intended for animal feed, but it is composed of matter, and valuable to the human diet. Approximate composition of the separated liquid whey is shown in Table. 10.7
|10.7 Table. The composition of the separated liquid whey|
The table shows that the dry substance to approximately serum 14% are composed of proteins that may be useful to some confectionery ingredient. Serum is sold in the form of whey paste (thickened serum) with 60-70% Content SC (whey). This pasta is pasteurized and packaged in plastic containers with a protective coating, and if the paste was made in compliance with the set conditions, it can be used within four weeks from the date of manufacture.
There are other serum products suitable for long term storage - is sweet whey paste and whey. Serum sweet paste is prepared by adding serum in an amount of sugar equal to the total content CB, after which condensation produced. Whey powder usually produced by spray drying; it just as roughly the shelf life and COM.
Whey contains large amounts of mineral salts, which is why when used in the confectionery composition in a large amount of these salts may cause an unpleasant aftertaste.
In recent years, beginning produced demineralized whey powder, from which the mineral salts are removed by means of electrodialysis or ion exchange. Such products are produced with varying degrees of demineralization and as a substitute COM in the product can be incorporated quite a large share of it. Examples of different formulations of dry demineralized whey are shown in Table. 10. 8.
|10.8 Table. Composition of dry demineralized whey|
Serum proteins described above consist essentially of a-lactalbumin and p-lactoglobulin. These proteins have a higher nutritive value and are used to produce certain types of dietary foods.
Reconstituted milk, skim milk with fillings (vegetable oil)
In a variety of pastry recipes can be used reconstituted milk. One of these technologies is described in the section “Milk sweets, toffee ...”. For the production of reconstituted milk is used instant COM and butter.
Skimmed milk with fillers consisting of COM and vegetable oil. After sufficiently dispersing the powdered milk in warm water is performed, and homogenization heat treatment (pasteurization, UHT). There are various applications of such milk, to which may also be added sugar, dextrose or lactose, resulting in sweetened condensed milk.
For production COM fillers with vegetable oil is emulsified in a solution of dry milk, followed by spray drying. A typical composition of the product (%) as follows:
Vegetable fats 25
Emulsifier, sugar 2
Moisture contents 3
Vegetable oils can be Lauric (coconut, palmkernel), or non-lauric (soybean). It is necessary to eliminate the impact of lipase lauric fats.
Other types of dairy products Solodovoe milk
Malted milk produced by heat treatment of the mash consisting of whole milk, barley malt and wheat flour. This technology is extremely important to adjust the temperature precisely about 65 ° C - otherwise formed unwanted products of side reactions.
There are other types of malted milk, made from milk, malt extract or a simple mixture of powdered milk and dried malt.
Yogurt. Currently, this product is widely represented in the sale - more often it adds flavors with a fruity taste and aroma. Generally, yogurt is made from skim milk dispersed, which is preheated for about 30 minutes at 88 ° C. After that produces homogenization and 43 ° C is added approximately 5% sugar and fruit juices or flavors, and then - leaven (L. bulgaricus), And then at the same temperature for 2-4 hours spend souring.
Enzyme-modified milk fat. In the US this product plays an important role as a flavoring for milk chocolate. Adjustable action of lipase to milk or dairy products gives the taste and aroma, which many people like. Properties similar products.
Currently available dry milk products that can be used as flavor additives in chocolate, milk chocolates, fudge and other similar confectionery.
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